Table 2.

Surgical and perioperative characteristics of infants enrolled in the NITric oxide during cardiopulmonary bypass to improve Recovery in Infants with Congenital heart defects (NITRIC) trial

Characteristics	Nitric oxide N =	Standard care N =	Difference (95% CI)
Cardiopulmonary bypass characteristics
Blood prime, n (%)
CPB duration (min), median (IQR)
CPB < 60 min, n (%)
CPB ≥ 60 min, n (%)
Cross-clamp, n (%)
Cross-clamp (min), median (IQR)
Number of CPB runs, n (%)
1
2
3
≥ 4
Deep hypothermic arrest, n (%)
Duration of deep hypothermic arrest (min), median (IQR)
Antegrade cerebral perfusion, n (%)
Modified ultrafiltration used, n (%)
Slow continuous ultrafiltration used, n (%)
Blood products received in theatre, median (IQR)
Red blood cells (mL/kg)
Whole blood (mL/kg)
Platelets (mL/kg)
Fresh frozen plasma (mL/kg)
Cryoprecipitate (mL/kg)
Drug treatments received in theatre, n (%)
Intravenous steroids
Inhaled NO
Administration of study drug (NO)
Time from start of CPB to start of NO (min), mean (SD)/median (IQR)
Duration of NO on CPB (min), median (IQR)
Proportion of time spent on CPB with NO,⁎ mean (SD)/median (IQR)
Change in methaemoglobin level (%) between start and post-CPB, mean (SD)/median (IQR)†
Change in methaemoglobin level (%) between start and post-CPB > 3%,†n (%)

CPB = cardiopulmonary bypass; IQR = interquartile range; NO = nitric oxide; SD = standard deviation.

^⁎If multiple CPB runs during the same surgery, summarising every CPB run individually.

^†Calculated as post-CPB methaemoglobin/pre-CPB methaemoglobin.